The importance of flow cytometry in the diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria / A importância da citometria de fluxo no diagnóstico e monitoramento da hemoglobinúria paroxística noturna

ABSTRACT Introduction: The paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disease of the hematopoietic stem cells, and it is clinically characterized by chronic intravascular hemolysis, bone marrow failure and hypercoagulability leading to thrombosis. It is a rare disorder of the hematopoietic stem cells that occurs due to a somatic mutation in the gene phosphatidylinositol glycan class A (PIG-A). Objective: Here we reviewed the importance of screening and monitoring of individuals with high risk of developing PNH, since the early diagnosis of the disease is essential for better prognostic and treatment choice for the patient. Method: A review was carried out with great focus on the pathophysiology and diagnosis of PNH, mainly with the use of flow cytometry technique to detect the disease. Results: This gene codifies an enzyme essential to the formation of glycosylphosphatidylinositol (GPI), which acts as a molecular anchor for many membrane proteins. The alteration of GPI synthesis promotes a partial or complete loss of proteins that needs this molecular anchor to bind to the cell surface. Among these proteins are the CD55 and the CD59, which control the activation of the complement cascade. Conclusion: The immunophenotyping exam with flow cytometry is considered the reference test for PNH diagnosis, since the technique is highly sensitive and specific, presenting advantages as the quantitative identification of small populations of cells with PNH phenotype and the capacity to distinguish cells with partial or total deficiency of GPI-anchored proteins.

RESUMEN Introducción: La hemoglobinuria paroxística nocturna (HPN) es una enfermedad clonal adquirida de células madre hematopoyéticas; se caracteriza clínicamente por hemólisis intravascular crónica, insuficiencia medular e hipercoagulabilidad, que conduce a trombosis. Es un trastorno raro de las células madre hematopoyéticas que ocurre debido a una mutación somática en el gen fosfatidilinositol-glicano de clase A (PIG-A). Objetivo: Este estudio tuvo como objetivo revisar la importancia del cribado y seguimiento de individuos con alto riesgo de desarrollar HPN, pues el diagnóstico precoz de la enfermedad es vital para un mejor pronóstico y la elección del tratamiento del paciente. Métodos: Se realizó una revisión con mayor enfoque en la fisiopatología y diagnóstico de la HPN. El foco principal de la investigación fue el uso de la técnica de citometría de flujo para detectar la enfermedad. Resultados: Ese gen codifica una enzima esencial en la formación de glicosilfosfatidil inositol (GPI), que actúa como molécula de anclaje para varias proteínas de membrana en las células hematopoyéticas. Cambiar la síntesis de GPI genera una pérdida parcial o total de proteínas que necesitan esta molécula de anclaje para unirse a la superficie celular. Entre esas proteínas se encuentran CD55 y CD59 presentes en los eritrocitos, que controlan la activación de la cascada del complemento. Conclusión: La técnica de inmunofenotipificación por citometría de flujo se considera la prueba de referencia para el diagnóstico de HPN, ya que es altamente sensible y específica, presenta ventajas como la identificación cuantitativa de pequeñas poblaciones de células con el fenotipo de HPN y la capacidad de distinguir células con deficiencia parcial o total de proteínas ancladas por GPI.

RESUMO Introdução: A hemoglobinúria paroxística noturna (HPN) é uma enfermidade clonal adquirida de células-tronco hematopoiéticas; caracteriza-se clinicamente por hemólise intravascular crônica, falência medular e hipercoagulabilidade, levando a tromboses. É uma rara desordem das células-tronco hematopoiéticas que ocorre devido a uma mutação somática no gene fosfatidilinositol glicano classe A (PIG-A). Objetivo: Este trabalho teve como objetivo revisar a importância do rastreamento e monitoramento de indivíduos com alto risco de desenvolvimento da HPN, pois o diagnóstico precoce da doença é essencial para um melhor prognóstico e a escolha do tratamento para o paciente. Metodologia: Foi realizada uma revisão com mais enfoque na fisiopatologia e no diagnóstico da HPN. O foco principal da pesquisa foi o uso da técnica da citometria de fluxo para a detecção da doença. Resultados: Esse gene codifica uma enzima essencial na formação de glicosilfosfatidil inositol (GPI), a qual atua como molécula âncora de diversas proteínas de membrana nas células hematopoiéticas. A alteração da síntese de GPI gera uma perda parcial ou completa de proteínas que necessitam dessa molécula-âncora para se ligarem à superfície celular. Entre estas proteínas estão o CD55 e o CD59 presente em eritrócitos, que controlam a ativação da cascata do complemento. Conclusão: O exame de imunofenotipagem por citometria de fluxo é considerado o teste de referência para diagnóstico de HPN, pois a técnica é altamente sensível e específica, apresentando vantagens como a identificação quantitativa de pequenas populações de células com fenótipo HPN e a capacidade de distinguir células com deficiência parcial ou total de proteínas ancoradas pela GPI.

Estudo Pioneiro sobre a Presença de Clone de Hemoglobinúria Paroxística Noturna durante Acompanhamento Terapêutico de Leucemia Aguda / Pioneering Study about the Presence of Paroxysmal Nocturnal Hemoglobinuria Clone during Therapeutic Monitoring of Acute Leukemia / Estudio Pionero sobre la Presencia de un Clon de Hemoglobinuria Paroxística Nocturna durante el Seguimiento Terapéutico de la Leucemia Aguda

Introdução: O potencial de transformação maligna de células-tronco hematopoiéticas portadoras de mutações no gene glicosilfostatidilinositolclasse A (PIG-A) para leucemias agudas, embora raro, já é bem descrito na literatura. Objetivo: Neste estudo, porém, buscou-se evidenciar pela primeira vez na literatura o surgimento ou a manutenção de clones de hemoglobinúria paroxística noturna (HPN) em pacientes diagnosticados com leucemia aguda ou ainda após o início do tratamento quimioterápico. Método: A pesquisa de clones de HPN foi realizada por citometria de fluxo em blastos, hemácias, granulócitos ou monócitos de 47 amostras de sangue periférico e medula óssea de pacientes submetidos à investigação diagnóstica ou acompanhamento terapêutico, provenientes de dois hospitais oncológicos e públicos de Belém, no período de dezembro de 2017 a dezembro de 2018. Resultados: A presença de clones de HPN foi observada em 19/47 (40,4%) amostras de pacientes, em investigação diagnóstica ou acompanhamento terapêutico, que realizaram pelo menos um estudo de acompanhamento terapêutico e ainda tiveram o surgimento ou a manutenção do clone de HPN mesmo após iniciado o tratamento quimioterápico. Conclusão: Foi possível evidenciar, de forma primária, a presença de clones de HPN em pacientes diagnosticados com leucemia aguda tanto no período de investigação diagnóstica como durante o acompanhamento terapêutico, independentemente da ontogenia celular. Sem, porém, que se possa ainda avaliar a importância da presença desses clones de HPN para a evolução da doença primária, prognóstico ou necessidade de tratamento específico.

Introduction: The potential for malignant transformation of hematopoietic stem cells carrying mutations in theglycosylphosphatidylinositol class A (PIG-A) gene for acute leukemias, although rare, is already well described in the literature. Objective: In this study, however, it was attempted to show for the first time in the literature the emergence or maintenance of paroxysmal nocturnal hemoglobinuria (PNH) clones in patients diagnosed with acute leukemia or even after the beginning of the chemotherapy treatment. Method: The search of PNH clones was performed by flow cytometry in blasts, erythrocytes, granulocytes or monocytes of 47 samples of peripheral blood and bone marrow from patients undergoing diagnostic investigation or therapeutic follow-up in two oncological and public hospitals in Belém, from December 2017 to December 2018. Results: The presence of PNH clones was observed in 19/47 (40.4%) patient samples, in diagnostic investigation or therapeutic follow-up, who participated of at least one therapeutic follow-up study and still experience the appearance or maintenance of the PNH clone even after the beginning of the chemotherapy treatment. Conclusion: Primarily, it was possible to demonstrate the presence of PNH clones in patients diagnosed with acute leukemia both during the diagnostic investigation period and therapeutic follow-up, regardless of cell ontogeny. However, the importance of the presence of these PNH clones for the evolution of the primary disease, prognosis or need for specific treatment was not evaluated yet.

Introducción: El potencial de transformación maligna de las células madre hematopoyéticas que portan mutaciones en el gen glicosofosfatidilinositol (GPI) clase A (PIGA) para las leucemias agudas, aunque raro, ya está bien descrito en la literatura. Objetivo: En este estudio, sin embargo, buscamos mostrar por primera vez en la literatura la aparición o mantenimiento de clones de HPN en pacientes diagnosticados de leucemia aguda o incluso después del inicio de la quimioterapia. Método: La investigación de clones de hemoglobinuria paroxística nocturna (HPN) se realizó mediante citometría de flujo en blastos, eritrocitos, granulocitos o monocitos de 47 muestras de sangre periférica y médula ósea de pacientes sometidos a investigación diagnóstica o seguimiento terapéutico de dos hospitales oncológicos y públicos de Belém, durante el período. de diciembre de 2017 a diciembre de 2018. Resultados: La presencia de clones HPN se observó en 19/47 (40,4%) muestras de pacientes, en investigación diagnóstica o seguimiento terapéutico, que realizaron al menos un estudio de seguimiento terapéutico y aún tenían la aparición o mantenimiento del clon HPN incluso después de iniciado el tratamiento de quimioterapia. Conclusión: Se pudo evidenciar, de forma primaria, la presencia de clones de HPN en pacientes diagnosticados de leucemia aguda tanto durante el período de investigación diagnóstica como durante el seguimiento terapéutico, independientemente de la ontogenia celular. Sin embargo, no podemos todavía evaluar la importancia de la presencia de estos clones de HPN para la evolución de la enfermedad primaria, el pronóstico o la necesidad de un tratamiento específico.

Perinatal outcomes of paroxysmal nocturnal hemoglobinuria during pregnancy: cases report and literature review / 中华围产医学杂志

Objective:To explore the progression of paroxysmal nocturnal hemoglobinuria (PNH) during pregnancy and treatment for improving maternal and infant outcomes.Methods:Nine pregnant women with PNH were admitted to the Obstetrics Department of Peking University People's Hospital from September 2010 to September 2020. The clinical data of these patients were retrospectively collected and analyzed. Relevant literature was reviewed to summarize the progression, treatment, complications, perinatal outcomes, and follow-up of PNH during pregnancy. Descriptive methods were used for statistical analysis.Results:Among the nine patients, six were classic PNH, and three combined with bone marrow failure disease. Eight cases received blood transfusion/low-dose corticosteroids or combination therapy during pregnancy, and four of them were also received anticoagulants. In seven out of the eight patients diagnosed prenatally, the disease worsened during pregnancy. Complications were noted in eight patients during pregnancy, including fetal growth restriction in seven cases, hypertension and premature delivery in four cases each, thrombosis and intrauterine fetal death in one case each. No maternal deaths were reported, with a live birth rate of 8/9 between 33-38 gestational weeks, with the median at 37 weeks. The median time of postpartum follow-up was 50 months (4-92 months), during which the patients' conditions were all stable, and no abnormalities were found in the growth and development of the babies.Conclusions:Pregnant women with PNH tend to worsen with an increased incidence of perinatal complications and adverse outcomes. Multidisciplinary management is recommended for this population may help improve maternal and infant outcomes.

The case of eculizumab: litigation and purchases by the Brazilian Ministry of Health / O caso do eculizumabe: judicialização e compras pelo Ministério da Saúde

ABSTRACT OBJECTIVES This study examined the purchases of eculizumab, a high-cost monoclonal antibody used in the treatment of rare diseases by Brazilian federal agencies, in terms of purchased quantities, expenditures, and prices. METHODS Eculizumab purchases made between March 2007 and December 2018 were analyzed, using secondary data extracted from the Federal Government Purchasing System (SIASG in Portuguese). The following aspects were assessed: number of purchases, purchased quantities, number of daily doses defined per 1,000 inhabitants per year, annual expenditures, and prices. The prices were adjusted by the National Broad Consumer Price Index for December 2018. Linear regression was used for trend analysis. RESULTS All acquisitions by federal agencies were made by the Brazilian Ministry of Health. The purchases began in 2009 with tender waiver to comply with legal demand. There was an increasing trend in the number of purchases and quantities acquired over time. Two hundred and eighty-three purchases were made, totaling 116,792 units purchased, 28.2% of them in 2018. The adjusted total expenses summed more than R$ 2.44 billion. After market approval by the Brazilian Health Regulatory Agency, the weighted average price fell approximately 35%, to values under the Medicines Market Chamber of Regulation established prices. CONCLUSION Eculizumab represented extremely significant expenditures for the Brazilian Ministry of Health during the period. All purchases were made to meet demands from lawsuits, outside the competitive environment. The market approval of eculizumab promoted an important price reduction. This study indicates the relevance of licensing and the need for permanent monitoring and auditing of drug purchases to meet legal demands.

RESUMO OBJETIVOS O estudo examinou as aquisições de eculizumabe, um anticorpo monoclonal de alto custo utilizado no tratamento de doenças raras, pelos órgãos federais brasileiros, em termos das quantidades compradas, gastos e preços. MÉTODOS Foram analisadas compras de eculizumabe realizadas entre março de 2007 e dezembro de 2018, por meio de dados secundários extraídos do sistema de compras do governo federal (Siasg). Foram examinados o número de compras, quantidades adquiridas, número de doses diárias definidas por 1.000 habitantes por ano, gastos anuais e preços praticados. Os preços foram corrigidos pelo índice nacional de preços ao consumidor amplo para dezembro de 2018. Regressão linear foi utilizada para análises de tendência. RESULTADOS Todas as aquisições por órgãos federais foram realizadas pelo Ministério da Saúde. As compras se iniciaram em 2009, sendo efetuadas por dispensa de licitação e para atendimento de demanda judicial. Houve tendência crescente no número de compras e quantidades adquiridas ao longo do tempo. Foram realizadas 283 compras, totalizando 116.792 unidades adquiridas, 28,2% compradas em 2018. Os gastos totais contratados corrigidos somaram mais de R$ 2,44 bilhões. Após a aprovação do registro pela Agência Nacional de Vigilância Sanitária, o preço médio ponderado caiu aproximadamente 35%, para valores abaixo dos preços estabelecidos pela Câmara de Regulação do Mercado de Medicamentos. CONCLUSÃO O eculizumabe representou gastos extremamente significativos para o Ministério da Saúde no período. Todas as compras foram feitas para atendimento de demandas judiciais, fora do ambiente competitivo. Seu registro promoveu queda importante nos preços praticados. O estudo aponta a relevância do registro sanitário e da necessidade de monitoramento e auditoria permanentes das compras de medicamentos para atendimento de demandas judiciais.

Comparison of haploidentical hematopoietic stem cell transplantation and matched-sibling donor transplantation for the treatment of paroxysmal nocturnal hemoglobinuria / 中华血液学杂志

Objective@#To compare the outcomes between haploidentical donor hematopoietic stem cell transplantation (haplo-HSCT) and matched-sibling donor transplantation (MSD-HSCT) for paroxysmal nocturnal hemoglobinuria (PNH) .@*Methods@#The clinical data of 40 PNH patients received HSCT (haplo-HSCT=25, MSD-HSCT=15) from July 2007 to May 2018 were analyzed retrospectively to compare the outcomes between haplo-HSCT and MSD-HSCT groups.@*Results@#There were no differences in terms of gender, age, patients of PNH-AA and median time from diagnosis to transplantation between the 2 groups (P>0.05) . The median values of absolute mononuclear cell counts and CD34+ cells infused were 10.74 (4.80-22.86) ×108/kg and 12.19 (5.14-17.25) ×108/kg (P=0.866) , 3.57 (0.68-7.80) ×106/kg and 4.00 (3.02-8.42) ×106/kg (P=0.151) respectively, in haplo-HSCT and MSD-HSCT groups. All patients attained complete engraftment, no patient occurred graft failure. The median durations for myeloid and platelet engraftment were 12 (range, 9-26) and 11 (range, 7-15) days (P=0.065) , 19 (range, 11-75) and 13 (range, 11-25) days (P=0.027) respectively, in haplo-HSCT and MSD-HSCT groups. During a median follow-up of 26 (4-65) months in haplo-HSCT and 36 (4-132) months in MSD-HSCT groups (P=0.294) , the incidences of grade Ⅰ-Ⅳ acute graft-versus-host disease (aGVHD) were 32.0% and 20.0% (P=0.343) , grade Ⅱ-Ⅳ aGVHD were 16.0%, 13.3% (P=0.759) , chronic GVHD were 30.7% and 24.6% (P=0.418) , moderate-severe chronic GVHD were 12.7% and 7.1% (P=0.522) respectively, in haplo-HSCT and MSD-HSCT groups. The incidences of infection were 32.0% (8/25) and 26.7% (4/15) (P=1.000) respectively, in haplo-HSCT and MSD-HSCT groups. No patients occurred early death and relapse. Three-year estimated overall survival (OS) were (86.5±7.3) % and (93.3 ±6.4) % (P=0.520) , GVHD-free and failure-free survival (GFFS) were (78.3±8.6) % and (92.9±6.9) % (P=0.250) respectively, in haplo-HSCT and MSD-HSCT groups.@*Conclusion@#The preliminary results indicated that haplo-HSCT was a feasible choice for PNH with favorable outcomes, haplo-HSCT and MSD-HSCT produced similar therapeutic efficacy.

New topic of complement and diseases / 中华检验医学杂志

Complement system is involved in the pathogenesis of a group of diseases and also provides an important interface between the innate and adaptive immune response.Currently available tools provide an exciting opportunity to study this system,and some diseases were found to be resulted from excessive and uncontrolled activation of the complement of which the pathogenesis used to be unclear,such as paroxysmal nocturnal hemoglobinuria (PNH),atypical hemolytic uremic syndrome (aHUS) and C3 glomerulopathy (C3G),etc.Several complement inhibitors have been approved for clinical use,and additional complement inhibitory drugs are in development.The use of these drugs in patients will expand our understanding of the benefits and limitations of complement inhibition in human diseases.

A Successful Planned Pregnancy and Delivery with Eculizumab Maintenance in a Woman with Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is a hematologic disorder characterized by complement-mediated hemolysis leading to severe complications, such as life threatening thrombosis. Eculizumab, a humanized anti-C5 monoclonal antibody, has dramatically improved outcomes of patients with PNH. Despite this new revolutionary treatment, clinical information regarding eculizumab use in pregnant women with PNH is limited. A 30-year-old female with PNH underwent acute aggravation of PNH presented with acute kidney injury (AKI) triggered by an infectious event. After the stabilization of AKI with supportive care and later continuous eculizumab use, a planned pregnancy was attempted and achieved because she and her spouse wanted to have a baby. We monitored the patient carefully throughout her pregnancy with 100 mg/day of aspirin and the maintenance of 900 mg of intravenous eculizumab every 2 weeks. She remained stable during pregnancy and a successful delivery was achieved without maternofetal complication.

Paroxysmal nocturnal hemoglobinuria clone in 103 Brazilian patients: diagnosis and classification

Background: Paroxysmal nocturnal hemoglobinuria is an acquired chronic hemolytic ane- mia, which often manifests as peripheral blood cytopenias and thrombosis. Objective: The aim of this study is to describe a Brazilian population of paroxysmal nocturnal hemoglobinuria patients. Methods: One hundred and three paroxysmal nocturnal hemoglobinuria cases were retrospectively reviewed and the clinical presentation, thrombosis, survival, and clone size were assessed. Diagnosis was established by flow cytometry. Results: Fifty-two male and 51 female patients with a median age of 24.1 years (5.5-62 years) were studied. Clinical symptoms included hemoglobinuria (18.4%), infection (46.6%) and thrombosis (16.5%), and 80.6% had pancytopenia. Patients were classified as classic parox- ysmal nocturnal hemoglobinuria (10), paroxysmal nocturnal hemoglobinuria with aplastic anemia (39), and paroxysmal nocturnal hemoglobinuria with subclinical features and aplas- tic anemia (54). There were significant differences in terms of median age, size of clone, clinical symptoms, and peripheral blood cell counts between the three subcategories. The clone size in erythrocytes and granulocytes were respectively 0.04% (range: 0-18%) and 7.3% (range: 0.3-68.7%) in patients with subclinical features and aplastic anemia, 15.8% (range: 0-99.7%) and 63.0% (range: 1.7-99.8%) in patients with aplastic anemia alone, and 82.2% (range: 0-99.85%) and 98.0% (81.3-100.0%) in Classic disease. Statistical differences were identified for platelets (p-value = 0.001), lactate dehydrogenase (p-value = 0.002) and the clone size (p-value < 0.001) in patients who suffered thrombotic events compared to those who did not. Overall survival was 81.7%, with patients with subclinical features and aplastic anemia having lower overall survival (76.5%). Conclusion: This retrospective review of 103 patients over an 11-year period represents the largest collection of paroxysmal...

Paroxysmal nocturnal hemoglobinuria with cerebral venous sinus thrombosis:a case report and literature review / 国际脑血管病杂志

Paroxysmalnocturnalhemoglobinuria(PNH)isadefectdiseaseofacquiredclonal hematopoietic stem cel s. It can be expressed as hemolytic anemia, hemoglobinuria, and venous thrombosis. Cerebral venous sinus thrombosis (CVST) is a rare but serious complication of PNH. Here we report a PNH patient with CVST and reviewthe relevant literature. For patients who have the risk factors for CVST and neurological symptoms, such as headache and increased intracranial pressure, should early conduct brain imaging examination and make the diagnosis clear, and give an active treatment in the aspects of anticoagulation, dehydration, eliminating the causes of disease, and controling complications.

Detecting the AChE content of RBC and plasma in the people with paroxysmal nocturnal hemoglobinuria / 中国实用内科杂志

Objective Detect the AChE content of RBC and plasma in the people with PNH.Invstigate the effect of the enzyme in GPI on PNH.Methods Detect the activity of AChE in RBC and plasma in 30 patients with PNH.Results (1)The activity of AChE of RBC in PNH patients was higher than controls,the difference between them having statistic significance,P

Membranous Glomerulopathy as a Manifestation of Chronic Graft-versus-Host-Disease After Non-myeloablative Stem Cell Transplantation in a Patient with Paroxysmal Nocturnal Hemoglobinuria

Allogeneic stem cell transplantation (allo-SCT) using related or unrelated donor could eradicate paroxysmal nocturnal hemoglobinuria (PNH) clones and may cure the disease. Chronic graft-versus host disease (GVHD) is a major complication of patients who have undergone allo-SCT. Nephrotic syndrome has been described as one of the rare manifestations of chronic GVHD following the usual myeloablative allo-SCT. We report a case of nephrotic syndrome that developed 25 months after non-myeloablative allo-SCT for PNH. The patient had grade II acute GVHD and extensive chronic GVHD after non-myeloablative allo-SCT. Typically the patient presented with preserved renal function and full nephrotic syndrome including generalized edema, proteinuria, hypoalbuminemia, and hypercholesterolemia. Renal biopsy revealed findings of membranous glomerulopathy (MG). The patient is alive with a stable engraftment and full donor chimerism under the administration of tacrolimus for control of chronic GVHD and MG without refractory hemolysis and cytopenia.